1. Field of the Invention
The present invention relates to a variable magnification device and a telescopic sight using the same, and more particularly, to a variable magnification device which is capable of easily adjusting a magnification of a telescopic sight under a condition where a shooter aims for a target with a telescopic sight, and a telescopic sight using the same.
2. Description of the Related Art
A telescopic sight refers to a sighting telescope which is a device which magnifies and aims for a remote target precisely with it attached to a firearm such as a rifle
As used therein, the term “rifle” refers to a personal firearm which has a bored barrel loaded with bullets, shoots with it put on a shoulder of a shooter, and which is capable of hitting a target precisely with an elaborative sight
Such sight of the rifle is generally obtained by alignment of a line of sight aimed at a target, which is an important step of determining precise shooting in which a front sight located at an end of barrel is aligned with a back sight located in a main body of the rifle.
However, since the front sight and the back sight are very small and their alignment may be in disorder due to small shaking, a shooter requires extreme concentration for alignment of the line of sight.
In addition, as the shooter is excessively concerned about the alignment of the line of sight, the shooter's eyes are focused on the front sight and the back sight rather than the target and forward situations, which results in a narrow field of vision.
In addition, the line-of-sight alignment takes a relatively long time, which is against the nature of shooting that a secured target has to be instantaneously hit.
Accordingly, to overcome these problems, in the related art, a telescopic sight has been attached to a rifle.
Such a telescopic sight eliminates the need of separate line-of-sight alignment by adding coordinate lines or points to the telescopic principle and can aim at a remote target by increasing a magnification from low to high.
A structure of this telescopic sight will be described in brief below with reference to FIG. 1.
A conventional telescopic sight may have a body consisting of a series of objective barrel 10, middle barrel 20 and ocular barrel 30. The objective barrel 10 includes an objective bunch 11, the middle barrel 20 includes a creak bunch 21 and an internal bunch 23, and the ocular barrel 30 includes an ocular bunch 31 and a reticle bunch 33.
Optical lenses are respectively mounted within the objective bunch 11, the internal bunch 23 and the ocular bunch 31 and a zoom lens 25 is mounted within the internal bunch 23.
The zoom lens 25 is moved by a zoom front wheel rotated along the circumference of the middle barrel 20, thereby changing a magnification of the telescopic sight.
That is, the magnification of the telescopic sight is adjusted by the rotation of the zoom front wheel 27.
However, it is difficult for the zoom front wheel 27 to be rotated at an aiming posture.
This is because it is not easy to find a position of the zoom front wheel 27 only with the feel of hands at the aiming posture at which the eye is concentrated on the inside of the ocular barrel 30.
In addition, it is difficult for the zoom front wheel 27 to turn with one hand since it is stiffly mounted such that it is not randomly rotated by shooting vibration of the rifle.
In the end, the shooter has to turn the zoom front wheel 27 with one hand after the shooter takes his/her eye off the ocular barrel 30 and distracts his/her aiming posture.
Moreover, the zoom front wheel 27 has to be finely turned with one hand for an elaborate focus adjustment, which is not an easy work in the aiming posture.